Porting NFB drivers from SCO OpenServer 5 to SVR5

Porting NFB drivers from SCO OpenServer 5 to SVR5

Porting an NFB X server driver from an SCO OpenServer 5 to a SVR5 environment is very simple. With only a few #ifdef statements, the same code can compile on both platforms. Starting from existing source, it usually takes less than one hour to get a package-installable driver running on a SVR5 system.

NOTE: When X Consortium code was modified for SCO OpenServer 5 systems, the directive #if defined(sco) was used to identify SCO-specific code. For SVR5, the directive #if defined(usl) selects code for the SVR5 X11R6 environment.

In almost all cases, SCO-specific code from SCO OpenServer 5 continues to apply in the SVR5 environment. Some X11R6 code in the SVR5 environment may continue to contain #if defined(sco) statements; this code is valid and is included for compiles on SVR5. Therefore, #if defined(sco) is valid for both SCO OpenServer 5 and SVR5, while #if defined(usl) is specifically for SVR5 and is excluded in the SCO OpenServer 5 environment.

To port your SCO OpenServer 5 NFB X server driver to SVR5:

Create a directory tree for the ported driver using the xmkddx shell script as described in ``Set up the driver source tree and create a driver template''.
Copy your SCO OpenServer 5 source code into the ./ports directory created by xmkddx.
Make the following modifications (as necessary) to your driver source to allow it to compile without errors in the SVR5 X Link Kit environment. To ensure that it will continue to compile on SCO OpenServer 5 systems, surround the changes with #if defined(usl) as shown in these examples:
- SCO OpenServer 5 code includes these #include statements:
```
   #include "servermd.h"
   #include "misprite.h"
   #include "mipointer.h"
```
  They must be modified on SVR5 systems:
```
   #include "servermd.h"
   #if defined(usl)
   #include "mi.h"
   #endif
   #include "mipointer.h"
   #include "misprite.h"
```
- The ioctl(1, SW_VGA12, 0); ioctl statement should be removed for SVR5:
```
   #if ! defined(usl)
   	ioctl(1, SW_VGA12, 0);
   #endif
```
- This ioctl is associated with the header file console.h, which should be replaced by types.h and kd.h:
```
   #if defined(usl)
   #include <sys/types.h>
   #include <sys/kd.h>
   #else
   #include <sys/console.h>
   #endif
```
- The VOLATILE define was sometimes used on SCO OpenServer 5 systems to control the use of the ``volatile'' directive to the compiler. To enable this keyword for the SVR5 build environment, define it as follows:
```
   #if defined(usl)
   #define VOLATILE volatile
   #endif
```
- The SCO OpenServer 5 header file compiler.h must be replaced by types.h and inline.h:
```
   #if defined(usl)
   #include <sys/types.h>
   #include <sys/inline.h>
   #else
   #include "compiler.h"
   #endif
```
- Although rarely implemented, the PCI bus registers can be accessed directly via the /dev/pci device on SCO OpenServer 5 systems:
```
   #define PCI_DEV "/dev/pci"
   #include <sys/pci.h>
```
  If you have done so, modify the code for SVR5 systems:
```
   #if defined(usl)
   #define PCI_DEV "/dev/X/pci"
   #include <pcix.h>
   #else
   #define PCI_DEV "/dev/pci"
   #include <sys/pci.h>
   #endif
```
  The ioctl access to this PCI device remains the same on SVR5 systems.

The driver's Imakefile must be changed, protecting an SCO OpenServer 5 code passage with #ifdef statements and adding new code for SVR5 systems. In this example, xxx refers to your driver name.

   #if defined(USLArchitecture)
   
   STD_DEFINES = ServerDefines XDriverDefines -DVOLATILE=volatile
      INCLUDES = -I. -I../.. -I$(SERVERSRC)/include \
           -I$(SERVERSRC)/hw/sco/include \
           -I$(SERVERSRC)/hw/sco -I$(SERVERSRC)/hw/sco/nfb \
           -I$(SERVERSRC)/hw/sco/ports/gen -I$(INCLUDESRC) \
           -I$(SERVERSRC)/mi -I$(SERVERSRC) -I$(FONTINCSRC)
      LINTLIBS = $(SERVERSRC)/dix/llib-ldix.ln $(SERVERSRC)/os/4.2bsd/llib-los.ln \
                $(SERVERSRC)/ddx/mfb/llib-lmfb.ln $(SERVERSRC)/ddx/mi/llib-lmi.ln
       DDXLIBS = libxxx.a
   

   all::
           LibMkdir(shared)
   

   clean::
           LibCleanDir(shared)
   

   .c.o:
           LibObjCompile(shared,-Kpic $(CDEBUGFLAGS))
           NormalLibObjCompile($(NOOP_))
   

   #ifndef SCP_PRODUCT
   NormalLibraryTarget(xxx,$(OBJS))
   SharedXDriverTarget(xxx,6.0,$(OBJS),shared,..)
   #endif
   LintLibraryTarget(xxx,$(SRCS))
   NormalLintTarget($(SRCS))
   DynamicObjectRuleSCP(xxx,libxxx.a,xxxInit.c)
   

   #else /* USLArchitecture */
   

   STD_DEFINES = ServerDefines
      INCLUDES = -I. -I$(SERVERSRC)/sys/common -I$(SERVERSRC)/ddx \
            -I$(SERVERSRC)/ddx/ports -I$(SERVERSRC)/include -I$(FONTSRC)/include \
            -I$(INCLUDESRC)
   

      LINTLIBS = $(SERVERSRC)/dix/llib-ldix.ln $(SERVERSRC)/os/4.2bsd/llib-los.ln \
                $(SERVERSRC)/ddx/mfb/llib-lmfb.ln $(SERVERSRC)/ddx/mi/llib-lmi.ln
   

   ... for about 42 lines, ending:
   

   #endif /* DebugServer */
   

   NormalLibraryTarget(xxx,$(OBJS))
   LintLibraryTarget(xxx,$(SRCS))
   

   NormalLintTarget($(SRCS))
   

   DynamicObjectRule(xxx,$(DDXLIBS))
   

   #endif /* USLArchitecture */